Conventionally, as a so-called twin-roller type sheet feeder in which a feed roller and a separation roller are integrally composed, there is such a type as shown in, for example, Patent Document 1. As shown in FIG. 15, the type has a spring clutch unit 107 based on a twisted coil spring 113 which is twined on the input hub 111 and the output hub 112, and the spring clutch unit 107 is fixed to the rotating shaft 104 of a feed roller 101 by setting the output hub 111 by means of a screw 114. The type has a delivery roller 102 which is caused to go up and down by swinging the frame 106 with the delivery roller 102 retained by the output hub 112.
[Patent Document 1] Japanese Published Unexamined Patent Application No. H6-72581